1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor light-emitting device, and particularly to a method of manufacturing a II-VI compound semiconductor light-emitting device capable of emitting light of green or blue color.
2. Description of the Related Art
Recently, there is an increasing demand of recording/reproducing information on and from an optical disc or a magnetooptical disc at a high density with a high resolution. Also, there is an increasing demand of a high-luminance display device and a low-loss optical fiber communication apparatus. Further, since there is an increasing trend of developing an optical analyzer for analyzing a DNA or a specific chemical substance, there is an increasing demand of developing a semiconductor light-emitting device capable of emitting light of green color or blue color as a light source of such optical analyzer.
As a material for making such a semiconductor light-emitting device capable of emitting light of green color or blue color, a II-VI compound semiconductor made of at least one of zinc (Zn), magnesium (Mg), beryllium (Be), cadmium (Cd) and mercury (Hg) of II-group elements and at least one of oxygen (0), sulfur (S), selenium (Se) and tellurium (Te) of VI-group elements is a promising material.
Of the above-mentioned materials, a material using a ZnMgSSe-based material is particularly promising as a cladding layer. A contact layer for ohmic-contacting an electrode is generally formed of a ZnTe layer or a superlattice structure containing the ZnTe layer (e.g. superlattice structure based on a ZnTe/ZnS superlattice and superlattice structure formed of a mixed crystal of ZnSeTe).
These structures are deposited by a MBE (molecular beam epitaxy) method, for example.
Therefore, since a crystallinity has not been satisfactory or the suppression of deterioration has not been sufficient, the semiconductor light-emitting device has been deteriorated when oscillated to emit laser beams. There is then the problem that the life time of the conventional semiconductor light-emitting device cannot be extended.
In the prior art, one of the causes that the semiconductor light-emitting device, e.g. semiconductor laser is deteriorated is mainly the deterioration or breakage of the inside of an active layer or the peripheral portion of the active layer. There is then the problem that it becomes more difficult to extend the life time of the semiconductor light-emitting device.